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Finding the Fourth Proportional to 787.38, 1,086.60 and 438.09

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Solution

The fourth proportional to 787.38, 1,086.60 and 438.09 is: 604.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.38 : 1,086.60 = 438.09 : x
  2. Step 2: Convert to fraction form
    787.38/1,086.60 = 438.09/x
  3. Step 3: Cross multiply
    787.38x = 1,086.60 × 438.09
  4. Step 4: Simplify right side
    787.38x = 476,028.59
  5. Step 5: Solve for x
    x = 476,028.59/787.38
  6. Step 6: Final answer
    x = 604.57

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.